关键词: 沙尘暴, 多尺度分析, 小波分析, 河西走廊

Abstract: Wavelet Analysis is a developing technology in the field of time-frequency analysis, which has the features of multi-time scales, multi-levels and multi-resolutions. Sand-dust storms periodically change in different space and time scales, and it is difficult to accurately simulate it by means of the traditional methods. Using the method of wavelet analysis, this paper discusses the series data of sand-dust storms in recent 30 years and the influencing variables including gales, drought, precipitation and air temperature. The wavelet analysis shows that sand-dust storms and climatic variables alternate obviously in multi-time scales. Time series of all the climatic variables are in-phase, but their main periods are different. Periodic oscillations of 7 years for sand-dust storms and gales dominate over other scales, correspondingly 13~25 years periodic oscillations of drought indices and precipitation and temperature variations are in the dominance. According to the periodical trends of the sand-dust storms, the Gansu Corridor will receive the sand-dust storms above normal level as a whole, but the increasing capability will be quite finite. This paper reveals that variability of sand-dust storms are more complicated than drought and precipitation and temperature, and gales have the prominent controls on sand-dust storms than other climatic variables, which influence sand-dust storms mainly on the long-tern scales. The research also illustrates that wavelet analysis offers a novel method of exploring the trends of the sand-dust storms, and the method could potentially has the ability to forecast the climatic variations.

Key words: sand-dust storms, multi-scale analysis, wavelet analysis, Gansu Corridor